/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * @test

 * @bug 8170708

 * @summary javap -m <module> cannot read a module-info.class

 * @library /tools/lib

 * @modules

 *      jdk.compiler/com.sun.tools.javac.api

 *      jdk.compiler/com.sun.tools.javac.main

 *      jdk.jdeps/com.sun.tools.classfile

 *      jdk.jdeps/com.sun.tools.javap

 * @build toolbox.JavacTask toolbox.JavapTask toolbox.ToolBox toolbox.TestRunner

 * @run main TestClassNameWarning

 */

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.Arrays;

import java.util.List;

import java.util.regex.Pattern;

import java.util.stream.Collectors;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.ClassWriter;

import toolbox.JavacTask;

import toolbox.JavapTask;

import toolbox.Task;

import toolbox.TestRunner;

import toolbox.ToolBox;

public class TestClassNameWarning extends TestRunner {

    public static void main(String... args) throws Exception {

        new TestClassNameWarning().runTests(m -> new Object[] { Paths.get(m.getName()) });

    }

    private ToolBox tb = new ToolBox();

    TestClassNameWarning() {

        super(System.err);

    }

    /**

     * Baseline test for normal classes.

     */

    @Test

    public void testStandardClass(Path base) throws Exception {

        Path src = base.resolve("src");

        Path classes = Files.createDirectories(base.resolve("classes"));

        tb.writeJavaFiles(src, "class A { }");

        new JavacTask(tb)

                .outdir(classes.toString())

                .files(tb.findJavaFiles(src))

                .run()

                .writeAll();

        List<String> log = new JavapTask(tb)

                .classpath(classes.toString())

                .classes("A")

                .run()

                .writeAll()

                .getOutputLines(Task.OutputKind.DIRECT);

        checkOutput(log, false, "^(Warning|Error)");

        checkOutput(log, true, "class A");

    }

    /**

     * Test that module-info can be used to name the .class file

     * for a module declaration (i.e. ACC_MODULE, this_class == 0)

     * This is the primary test case for the bug as reported.

     */

    @Test

    public void testStandardModuleInfo(Path base) throws Exception {

        Path src = base.resolve("src");

        Path classes = Files.createDirectories(base.resolve("classes"));

        tb.writeJavaFiles(src, "module m { }");

        new JavacTask(tb)

                .outdir(classes.toString())

                .files(tb.findJavaFiles(src))

                .run()

                .writeAll();

        List<String> log = new JavapTask(tb)

                .options("--module-path", classes.toString(),

                        "--module", "m")

                .classes("module-info")

                .run()

                .writeAll()

                .getOutputLines(Task.OutputKind.DIRECT);

        checkOutput(log, false, "^(Warning|Error)");

        checkOutput(log, true, "module m");

    }

    /**

     * Test module-info can still be used to find a weirdly named

     * class equivalent to "class module-info { }" if that were legal in JLS.

     * Such a class file would arguably be legal in certain selected contexts.

     */

    @Test

    public void testLegacyModuleInfo(Path base) throws Exception {

        Path src = base.resolve("src");

        Path classes = Files.createDirectories(base.resolve("classes"));

        tb.writeJavaFiles(src, "class module_info { }");

        new JavacTask(tb)

                .outdir(classes.toString())

                .files(tb.findJavaFiles(src))

                .run()

                .writeAll();

        byte[] bytes = Files.readAllBytes(classes.resolve("module_info.class"));

        byte[] searchBytes = "module_info".getBytes("UTF-8");

        byte[] replaceBytes = "module-info".getBytes("UTF-8");

        for (int i = 0; i < bytes.length - searchBytes.length; i++) {

            if (Arrays.equals(bytes, i, i + searchBytes.length,

                                searchBytes, 0, searchBytes.length)) {

                System.arraycopy(replaceBytes, 0, bytes, i, replaceBytes.length);

            }

        }

        Files.write(classes.resolve("module-info.class"), bytes);

        List<String> log = new JavapTask(tb)

                .classpath(classes.toString())

                .options("-bootclasspath", "") // hide all system classes

                .classes("module-info")

                .run()

                .writeAll()

                .getOutputLines(Task.OutputKind.DIRECT);

        checkOutput(log, false, "^(Warning|Error)");

        checkOutput(log, true, "class module-info");

    }

    /**

     * Test an invalid class, with this_class == 0.

     */

    @Test

    public void testNoNameClass(Path base) throws Exception {

        Path src = base.resolve("src");

        Path classes = Files.createDirectories(base.resolve("classes"));

        tb.writeJavaFiles(src, "class A { }");

        new JavacTask(tb)

                .outdir(classes.toString())

                .files(tb.findJavaFiles(src))

                .run()

                .writeAll();

        ClassFile cf = ClassFile.read(classes.resolve("A.class"));

        ClassFile cf2 = new ClassFile(

                cf.magic, cf.minor_version, cf.major_version, cf.constant_pool,

                cf.access_flags,

                0, // this_class,

                cf.super_class, cf.interfaces, cf.fields, cf.methods, cf.attributes);

        new ClassWriter().write(cf2, Files.newOutputStream(classes.resolve("Z.class")));

        List<String> log = new JavapTask(tb)

                .classpath(classes.toString())

                .classes("Z")

                .run()

                .writeAll()

                .getOutputLines(Task.OutputKind.DIRECT);

        checkOutput(log, true, "Warning:.*Z.class does not contain class Z");

    }

    /**

     * Test a class with unexpected contents.

     * This is the arguably the most common negative case.

     */

    @Test

    public void testWrongNameClass(Path base) throws Exception {

        Path src = base.resolve("src");

        Path classes = Files.createDirectories(base.resolve("classes"));

        tb.writeJavaFiles(src, "class A { }");

        new JavacTask(tb)

                .outdir(classes.toString())

                .files(tb.findJavaFiles(src))

                .run()

                .writeAll();

        Files.move(classes.resolve("A.class"), classes.resolve("B.class"));

        List<String> log = new JavapTask(tb)

                .classpath(classes.toString())

                .classes("B")

                .run()

                .writeAll()

                .getOutputLines(Task.OutputKind.DIRECT);

        checkOutput(log, true, "Warning:.*B.class does not contain class B");

    }

    /**

     * Check that the output does, or does not, contain lines matching a regex.

     */

    private void checkOutput(List<String> log, boolean expect, String regex) {

        Pattern p = Pattern.compile(regex);

        List<String> matches = log.stream()

                .filter(line -> p.matcher(line).find())

                .collect(Collectors.toList());

        if (expect) {

            if (matches.isEmpty()) {

                error("expected output not found: " + regex);

            }

        } else {

            if (!matches.isEmpty()) {

                error("unexpected output found: " + matches);

            }

        }

    }

}